Glossary of Pharmacology Terms

Absorption Rate Constant: The rate at which a medication is absorbed from dosage site to measurement location. This is applicable to all drugs except intravenous medications.

Accumulation, Accumulation Ratio: The amount of a medication found within a bodily fluid at a specific point when a steady state has been attained. The point of equality between drug administration and drug elimination.

Accuracy: The amount of error found in the results of a scientific equation.

Activity, Intrinsic: The quality of a drug that ascertains what the biological result will be. This is also referred to as intrinsic efficacy.

Addiction: A situation where use of a drug has changed the behavior and methods of the user, creating a need for it in order to continuing using or to obtain more of it.

Affinity: The extent to which one substance tends to want to bind with another.

Allergic Response: A situation in which the body forms antibodies against a specific drug, causing a physical reaction that may or may not be severe.

Amplification: The quantity of change in determined output per unit change in input.

Analgesic: A medication that alleviates pain without the patient losing consciousness.

Anesthetic: A medication that causes loss of sensation. This is sometimes used to alleviate pain or for loss of consciousness for surgical procedures.

Antagonism: The combined result of two drugs being less than the sum of the two drugs put together. In essence, the whole is less than the sum of its parts.

Area Under the Curve: The area on a graph that falls under the curve when plotting time after administration of a drug against the plasma concentration of a drug. It is used to estimate how long it takes for a drug to be removed from the body.

AUC: The abbreviation of Area Under the Curve, or, the area of a graph that falls under the curve when plotting administration of a drug against the plasma concentration of a drug.

Availability: Also referred to as bioavailability, this is the amount of a drug dosage that is absorbed into circulation after administration of a specific dosage.

Bo: On a graph, the slope that occurs when concentration is plotted against the drug half life (or C is plotted against t).

Bioassay or Biological Assay: Establishing the strength of a chemical, physical, or biological agent, by way of a biological marker.

Bioavailability: Also referred to as availability, this is the amount of a drug that is absorbed into circulation after administration of a specific dosage.

Biopharmaceutics: The study of how the pharmaceutical expression of certain drugs can impact their pharmacodynamic and pharmacokinetic behavior.

Biotransformation: The chemical change of a drug that happens due to the effects the body has on it.

Biotranslocation: The transfer and movement of drugs in and throughout biological organisms.

Blind Experiment: A type of experiment in which the participants are unaware of the drug doses or treatments involved, so as not to affect the outcome.

Ceiling: The maximum result of a drug within a bodily tissue, regardless of the volume of the drug administered.

Chemotherapy: The treatment of cancerous or parasitic illnesses, where the drug affects only the neoplastic cells or invading organisms.

Clearance: The amount of the bodily fluid from which a drug is eliminated or excreted.

Clinical Therapeutic Index: An assessment of a drug having more safety at an acceptable level of potency or more potency at an acceptable level of safety within the recommended drug dosage.

Compartment(s): The area within the body that a drug tends to dwell in after it has been absorbed.

Compliance: The level of cooperation of a patient when following a prescribed treatment regimen.

Cross-Over Experiment: A type of experiment in which each participant receives a test preparation. The preparations are then crossed between participants in order to calculate the effects of the test preparation through various participants.

CT Index: The measure of the effects of a drug as calculated by plotting drug concentration against time.

Dependence: A physical need to maintain administration of a specific drug in order to avoid withdrawal symptoms.

Disintegration Time: The time it takes for a drug tablet to dissolve into pieces of a set size or smaller.

Dissolution Time: The time it takes for a certain amount of a drug to be reduced to a solution from a solid form.

Distribution: The volume within a person in which the administrated drug appears to have been dispersed. Also known as volume of distribution.

Dosage Form: The physical structure and appearance in which the drug to be administered is in for use.

Dose: The amount or form of a drug that is given to a user.

Dose-Effect Curve: On a graph, this is the result of plotting the dose of a drug against its effect on the bodily system.

Dose-Duration Curve: On a graph, this is the result of plotting the dose of a drug against its duration of time in the body.

Drug: A substance used in the prevention and treatment of illness or disease.

Drug Abuse: The misuse of a drug resulting in potentially destructive consequences.

Drug Dependence: Also referred to addiction, this is a situation where use of a drug has changed the behavior and methods of the user, creating a need for it in order to continuing using or to obtain more of it.

Dummy: A form of treatment that is meant to have no effect on the user, yet imitates the contrasting drug in every way. This is also known as a placebo.

Effective: A situation where an administered drug is successful in attaining its purpose.

Efficacy: The ability of a medication to produce a change in its intended cell receptor.

Elimination Rate Constant: On a graph, this is the result of plotting the logarithms of concentration against time.

Equipotent: Being equally effective or equally able to produce the drug effect of certain strength.

Equivalence: When drugs provide identical results when administered in the same amount, or those that contain equal dosages of the same type of drug, yet are named differently.

Experiment: Also called a bioassay, this is the process of establishing the strength of a chemical, physical, or biological agent, by way of a biological marker.

First Order Kinetics: The relationship of the speed of a chemical reaction in proportion to the concentrations of the reactants.

First Pass Effect: The absorption of a drug through the liver or intestines when taken in through the gastrointestinal tract but before reaching systemic circulation.

Food and Drug Administration: A federal organization responsible for ensuring compliance with the Food, Drug and Cosmetic Act.

Generic Drugs: Drugs that have exactly the same ingredients and effectiveness as another, named drug or formulary.

Habituation: A psychological feeling of need for a certain drug due to its effects on the body.

Half-Life: The time it takes for a drug concentration within the body to be reduced by one half of its original amount.

Harrison Act: A federal law regulating the distribution, transport, and manufacture of all narcotics.

Hazard: A drug that has the ability to cause bodily harm.

Hypersensitivity: The necessary condition for a person to show an allergic response to a drug.

Hypnotic: A medication that produces an effect that causes a change in consciousness or is similar to a state of sleep.

Idiosyncratic Response: An abnormal response from a drug that is specific to the person having the response.

Infusion Kinetics: The plasma concentration of a drug over a long period of time as it is proportional to the rate of the drug administration and inversely proportional to the rate of excretion and the area through which the drug is distributed.

Intrinsic Activity: The quality of a drug that ascertains what the biological result will be. This is also referred to as intrinsic efficacy.

Latent Period or Latency: The period of time between administration of a drug and the time at which an effect is achieved.

Loading dose: The first dose of a series that is larger than subsequent doses.

Maintenance Dose: The doses in a series that follow the initial loading dose.

Median Effective Dose: The dose of a drug calculated to produce a result in 50 percent of the users of whom the drug was administered.

Metameter: A term used to label the measurement of change during biological testing.

Multiple Dose Regimens: A treatment schedule for a drug in which it is given at certain intervals.

Narcotic: A drug that is able to create an analgesic effect, which may sometimes induce an altered state of consciousness.

National Formulary: A reference publication produced by the American Pharmaceutical Association that gives standards of purity for each drug.

Negative Control Drug or Negative Control Procedure: A procedure incorporated into an experiment that it should not affect the experimental system in the same way as the independent variable.

Parameter: During an experiment, one of the components that can be controlled to remain constant throughout the procedure.

Pharmacodynamics: The study of how drugs produce their effects on the body.

Pharmacogenetics: The study of the inheritance of certain interactions from drugs on the human body.

Pharmacokinetics: The study of absorption, distribution, and biotransformation of drugs on the body.

Pharmacology: The study of the features and characteristics of drugs and medications.

Placebo: A form of treatment that is meant to have no effect on the user, yet imitates the contrasting drug in every way. This is also known as a dummy.

Positive Control Drug: A drug used in an experiment that has the expectation that its results will be similar to those of the independent variable.

Potency: The strength of a drug in terms of the concentration or amount administered.

Potentiation: A situation where the result of one drug is increased by the use of another drug that has no effect.

Priming Dose: The first dose of a series that is larger than subsequent doses.

Prodrug: A substance with little action that becomes more active after being in the body.

Precision: The accuracy with which certain values of input can be understood by measured values of output.

Receptors: The part of a cell that responds to an administered drug.

Reference Standard: A drug with specific aspects that is used as the foundation of comparison with other substances that have similar aspects.

Reliability: The degree to which the drug and organism relationship is reproducible if it is studied again under similar conditions.

Risk: The probability that damage will result from exposure to a specific agent.

Selectivity: The ability of a drug to affect one type of cell over others.

Sensitivity: The ability of a specific group to respond to a drug in a certain way compared to other organisms.

Side Effects: Undesirable effects from drug treatment that are not intended as part of the therapeutic effect.

Standard Drug: Establishing the strength of a chemical, physical, or biological agent, by way of a biological marker.

Specificity: The ability of a drug to show only one type of result.

Standardized Safety Margin: The amount of a drug that is effective in almost all of the population that must be surpassed in order to produce a fatal effect on a minimum amount of a population.

Supersensitivity: An excessive amount of sensitivity to a drug.

Synergy: The use of two drugs together provides a greater effect than the sum of the original drugs.

Tachphylaxis: The building of tolerance to a drug after repeated administrations.

Therapeutic Index: A number that measures the relative safety of a drug.

Therapeutics: The discipline and actions of returning patients to a healthy state.

Threshold Dose: A dose of a drug that is just enough to produce its desired effect.

Time Concentration Curve: On a graph, the time concentration curve is the relationship between the dose of a drug and its latency period.

Tolerance: The reduced effectiveness of a drug after repeated administrations.

Toxic Effects: An effect of a drug that is harmful or lethal to the user.

Toxicology: The study of the effects of poisonous substances on the body.

United States Pharmacopoeia: A reference book that defines approved drugs and sets standards for their purity.

Validity: The amount of error found in the results of a scientific equation.

Volume of Distribution: Also known as distribution, this is the volume within a person in which the administered drug appears to have been dispersed.

Zero Order Kinetics: A condition in which the speed of an enzymatic reaction is independent of the strength of the substrate.

For additional information, check out the following:

What is Pharmacology?: An explanation of the historical development of pharmacology from the University of Texas Health Science Center.

Yale School of Medicine: Information about the pharmacology program and examples of careers available for the pharmacology degree.